Biology

Photosynthesis in Plants

1,508 Questions

Photosynthesis is the biological process by which plants convert light energy into chemical energy. This page contains practice questions covering essential topics like chlorophyll, light reactions, and the pathways specific to plants. This material is crucial for medical entrance exams and academic assessments.

Chlorophyll and pigmentsLight reactionsCalvin cycleCAM plantsElectron transportPhotosynthesis factors

Photosynthesis in Plants Questions

Multiple choice

The effect of light on respiration is called

  1. true respiration

  2. transpiration

  3. phosphorylation

  4. photorespiration
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Photorespiration (also known as the oxidative photosynthetic carbon cycle, or C2 photosynthesis) is a process in plant metabolism which attempts to ameliorate the consequences of a wasteful oxygenation reaction by the enzyme RuBisCO.

Multiple choice

Which of the following organisms have bacteriochlorophylls a, b, c, g and f?

  1. Purple and green sulphur bacteria

  2. Red alga and rhodophyta

  3. Brown algae

  4. Green algae and higher plants
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bacteriochlorophylls a, b, c, g and f occur in various phosynthetic bacteria. They carry on photosynthesis but do not produce oxygen. These types of chlorophyll are found in green and purple sulphur bacteria and other photosynthetic bacteria.

Multiple choice

_________ do not liberate oxygen on photosynthesis.

  1. Blue-green algae

  2. Photosynthetic bacteria

  3. Phaeophyceae

  4. Euglenophyceae
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

They use substances other than water as hydrogen donors and consequently, liberation of oxygen does not take place in the process.

Multiple choice

Which of the following statements regarding the factors which affect photosynthesis is false?

  1. Increase in CO2 supply increases the rate of photosynthesis markedly.

  2. The maximum photosynthesis occurs in red part and minimum in green part of spectrum.

  3. Photosynthesis increases with temperature but declines with time.

  4. Oxygen accumulation speeds up photosynthesis.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Oxygen accumulation retards the rate of photosynthesis.  

Multiple choice

During photosynthesis,

  1. O2 evolved comes from CO2

  2. ATP is formed

  3. ATP is not formed

  4. water is required as a medium but it does not take part in photosynthesis

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

During photosynthesis, ATP is formed during the light reaction. 

Multiple choice

The carbon cycle is mainly the conversion of carbon dioxide, which is initiated by the fixation of carbon dioxide from the atmosphere through

  1. decomposition by microorganisms

  2. denitrification

  3. photosynthesis

  4. oxidisation

  5. respiration
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct answer. The carbon cycle is mainly the conversion of carbon dioxide which is initiated by the fixation of carbon dioxide from the atmosphere through photosynthesis.

Multiple choice

The green colour of leaves is due to the presence of

  1. carbon dioxide

  2. chlorophyll

  3. red light

  4. none of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Chlorophyll is the green pigment found in chloroplasts of plant cells and algae, responsible for absorbing light energy for photosynthesis. It reflects green light (which is why leaves appear green) while absorbing red and blue wavelengths. This pigment is essential for converting light energy into chemical energy during photosynthesis. Carbon dioxide is absorbed, not the color source, and red light is absorbed, not the color giver.

Multiple choice

Which of the following is an incorrect statement?

  1. Animal cells do not have chloroplasts.

  2. The opening and closing of stomata is a function of guard cells.

  3. Chlorophyll is the molecule that absorbs sunlight.

  4. Phloem is the outer layer of cells covering an organism.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement 4 is incorrect as phloem is the living tissue that carries organic nutrients in plants.

Multiple choice

The change of colour from green to red during ripening of tomatoes and chillies is due to

  1. transformation of chromoplasts into chloroplasts

  2. transformation of chloroplasts into chromoplasts

  3. transformation of chloroplasts into leucoplasts

  4. transformation of leucoplasts into chloroplasts

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct answer because green colour of tomatoes and chillies is due to chloroplast and this chloroplast gets converted into chromoplast.